Apparatus for the cold working of bar stock

Abstract

A machine bed supports stationary and rotary fixing means that are aligned for receiving bar stock therebetween. Electrical or electromechanical control means are provided for selecting and effecting, via a motor-driven step-down gear, exactly a predetermined amount of rotation of the rotary fixing means. Various detachable matching pieces hold opposite portions of the bar stock within the stationary and rotary fixing means, respectively, while the material is worked. Openings in the matching pieces positively fit the bar stock. The outer contour of the matching pieces permits insertion in the stationary and rotary fixing means for positive fit therein. A preferred embodiment of the apparatus serves the purpose of cold twisting square steel bars either singly or, for obtaining volutes, in bunches. Removal of worked bar stock is facilitated by a handwheel enabling the operator to manually counter-rotate the rotary fixing means by a selected small angle. A slide may be mounted on the machine bed for supporting two bending rollers whose position relative to each other and to a pulling roller engaged in the rotary fixing means can be adjusted as required for feeding and working bar stock between the bending and pulling rollers. For twirling the bar stock, a disk device carrying a plying tool and a self-locking excenter may be inserted in the rotary fixing means.

I claim: 
     
       1. An apparatus for the cold working of bar stock, comprising a bed support stationary fixing means and comprising rotary fixing means motor-driven via a step-down gear, said stationary and rotary fixing means being aligned and arranged for variable spacing with respect to each other and being provided each with detachable insertion means having a profile matching that of the bar stock to be worked, control means being provided fo effecting a predetermined amount of rotation of said rotary fixing means relative to said stationary fixing means, whereby one bar portion is held stationary while an opposite bar portion is wound in predetermined degree. 
     
     
       2. Apparatus according to claim 1, wherein said rotary fixing means include a chuck disk with a shaped central hole for receiving said detachable insertion means. 
     
     
       3. Apparatus according to claim 2, wherein said detachable insertion means comprise matching pieces each having a through hole matching the bar stock to be worked and further having a peripheral configuration matching the shape of said central hole. 
     
     
       4. Apparatus according to claim 2, wherein the shape of said central hole is a polygon. 
     
     
       5. Apparatus according to claim 1, wherein said stationary fixing means include a yoke aperture for receiving said detachable insertion means. 
     
     
       6. Apparatus according to claim 5, wherein said detachable insertion means comprise profiled insets having sockets matching a bar to be twisted and further having a peripheral configuration matching the shape of said yoke aperture. 
     
     
       7. Apparatus according to claim 5, wherein said bed supporting said stationary fixing means is substantially beam-shaped, and wherein said stationary fixing means comprise a carriage slidingly adjustable along said generally beam-shaped bed, said carriage consisting of a saddle positively riding on said bed and of an upper portion including said yoke aperture, locking means being provided for securing said saddle to said bed in a selected position thereto. 
     
     
       8. Apparatus according to claim 5, wherein the top of said detachable insertion means has an opening as wide as one dimension of the bar stock to be worked. 
     
     
       9. Apparatus according to claim 5, wherein a grip holder is provided for clamping said stationary fixing means when said detachable insertion means hold a bar to be worked. 
     
     
       10. Apparatus according to claim 6, said detachable insertion means having rounded edges in said profile at the side facing the bar twists, the contour of said rounded edges following the twisting curve. 
     
     
       11. Apparatus according to claim 3, wherein matching pieces are arranged at both ends of said central hole in said rotary fixing means. 
     
     
       12. Apparatus according to claim 1, said detachable insertion means being designed to simultaneously receive a plurality of bars. 
     
     
       13. Apparatus according to claim 12, wherein said detachable insertion means are adapted to positively receive a bunch of four bars of square section for twisting volutes. 
     
     
       14. Apparatus according to claim 1, wherein a slidingly adjustable stop riding on said bed is provided beyond said stationary fixing means, said stop being adapted to abut the free end of said bar stock during the working operation. 
     
     
       15. Apparatus according to claim 13, wherein a slidingly adjustable stop riding on said bed is provided beyond said stationary fixing means, said stop being adapted to abut the free end of said bar stock during the working operation. 
     
     
       16. Apparatus according to claim 14, wherein said stop includes a saddle positively riding on said bed and locking means for securing said saddle to said bed in a selected position thereto. 
     
     
       17. Apparatus according to claim 1, wherein said control means comprise electromechanical means governing said motor drive for said rotary fixing means. 
     
     
       18. Apparatus according to claim 1, wherein selection means are provided for selecting said predetermined amount of rotation of said rotary fixing means. 
     
     
       19. Apparatus according to claim 18, wherein said control means are adapted to respond only to said selection means being set for a predetermined amount of rotation. 
     
     
       20. Apparatus according to claim 19, said rotary fixing means including at least one cam for actuating a limit switch upon completion of said predetermined amount of rotation of said rotary fixing means, the actuation of said limit switch stopping said motor drive. 
     
     
       21. Apparatus according to claim 20, wherein said cam is arranged for adjustment in a circumferential direction of said rotary fixing means. 
     
     
       22. Apparatus according to claim 20, wherein coupling means are provided for adjustably supporting said cam, said coupling means being adapted to be locked to said rotary fixing means in a selected position relative thereto. 
     
     
       23. Apparatus according to claim 22, wherein said coupling means comprise a setting disk associated to said rotary fixing means and arranged for controlled angular positioning relative thereto. 
     
     
       24. Apparatus according to claim 23, wherein markings are provided for controlling the angular adjustment between said setting disk and said rotary fixing means. 
     
     
       25. Apparatus according to claim 23, wherein said setting disk has a corruguated circumference for manual adjustment thereof. 
     
     
       26. Apparatus according to claim 23, wherein coaxial bearing means are provided in said rotary fixing means for supporting said setting disk relative thereto, spring means being arranged for axial bias between said setting disk and said rotary fixing means. 
     
     
       27. Apparatus according to claim 20, wherein a relay circuit is provided that is adapted to be operated, by means of separate controls, for forward and reverse run of said motor drive, a circuit breaker being provided for effecting the stop of said motor drive upon the final preselected actuation of said limit switch by said cam. 
     
     
       28. Apparatus according to claim 27, wherein said limit switch and said circuit breaker are mechanically coupled. 
     
     
       29. Apparatus according to claim 27, wherein resetting means are provided for said relay circuit. 
     
     
       30. Apparatus according to claim 18, said selection means comprising a counter. 
     
     
       31. Apparatus according to claim 1, wherein said control means include timing means for selecting and effecting said predetermined amount of rotation of said rotary fixing means. 
     
     
       32. Apparatus according to claim 31, wherein said timing means comprise a timer having interchangeable control elements for adaptation of said predetermined amount of rotation to the speed of said motor-driven gear. 
     
     
       33. Apparatus according to claim 1, wherein a handwheel is provided at the shaft of said motor for manually advancing and moving backward said rotary fixing means. 
     
     
       34. Apparatus according to claim 1, said control means being arranged laterally in respect of said supporting bed. 
     
     
       35. Apparatus according to claim 2, wherein a bending device is provided comprising a slide mounted on said bed, said slide supporting two bending rollers for conrolled spacing therebetween, means being provided for vertically adjusting said bending rollers relative to a pulling roller, the latter having insertion means positively matching said central hole, said pulling roller being adapted to cooperate with said bending rollers for gripping and cold working a bar therebetween. 
     
     
       36. Apparatus according to claim 35, said slide comprising at each side of said bed an inclined track directed towards said pulling roller, each track supporting a fixture for pillowing the associated bending roller, each fixture including a worm drive for adjusting the height and spacing of said bending rollers relative to each other and to said pulling roller. 
     
     
       37. Apparatus according to claim 35, wherein the circumference of said pulling roller is corrugated. 
     
     
       38. Apparatus according to claim 2, wherein twirler means are provided comprising a plug-in profile matching said central hole, said twirler means including an eccentric clamp comprising a rotatably mounted, corrugated eccentric cam adjacent which at least one plying tool is rigidly connected to said twirler means. 
     
     
       39. Apparatus according to claim 38, said twirler means consisting of a receiver disk bearing said plug-in profile and of a base disk interchangeably secured to said receiver disk. 
     
     
       40. Apparatus according to claim 39, wherein keying and locking means are provided for detachably interconnecting said receiver and base disks. 
     
     
       41. Apparatus according to claim 39, wherein support means are provided for holding backing-up means such that the latter extend substantially parallel to the axis of rotation of said twirler means at a given radial distance thereto. 
     
     
       42. Apparatus according to claim 39, wherein said base disk is integral with said plying tool inside which siad eccentric cam is supported for free rotation so as to jam a bar to be worked upon rotary movement of said twirler means.